It has been known to employ a transformer in various devices such as flash discharge lamps, photographic cameras, lighting equipment, and general electric communications systems. Because many of these devices are small, there has been a continual effort to reduce the overall dimensions of the transformers used therein without reducing the electrical capabilities of the transformer. Some of this effort has centered on reducing the size of the transformer core as a means of reducing the size of the transformer.
Prior art transformer have generally been of the E--E core configuration type as illustrated in FIG. 1(a), or the E-I configuration illustrated in FIG. 2(a). These core configurations have coils wound thereon as illustrated in FIG. 1(b) and FIG. 2(b), respectively.
The overall size of the transformer depends to a large extent upon the length and the width of the core 1 and, as stated, there have been attempts to reduce the dimensions of the transformer by reducing the dimensions of the core 1. It has been found, however, that such redesign is not without limits because a material reduction in the dimensions of the core 1 significantly affects its mechanical strength and can result in cores which do not contain a sufficient amount of iron to exhibit the proper electrical properties.
Specifically, excessive reduction of the core legs in their cross-section, particularly in the cross-section of the side legs 1a, 1b, often leads to damage to the core 1 in the course of manufacturing, or to the transformer as a whole because the core 1 is made of ferrite having a high magnetic permeability. For these reasons, it is customary to limit the cross-section of the core in commercial products to a range between 5.76 mm.sup.2 and 8.82 mm.sup.2.
Referring again to FIGS. 1(a) and 2(a) the central leg 1c is commonly formed to have a cross-section twice as large as the cross-section of each of the side legs 1a, 1b, and sufficient spacing must be provided between the central leg 1c and the side legs 1a, 1b to provide space for the core winding. Moreover, the requirement that the central leg 1c include at least a specific amount of iron in order to enable the desired output from the transformer places a distinct limit on the amount that the cross-section of the central leg 1c can be reduced.